By Dr Scott Claxton, Respiratory Physician, Joondalup
Respiratory diseases are common and, although they may not seem overtly severe, can still impact the patient’s sleep.
This may be as a part of the disease, for example pulmonary fibrosis and nocturnal hypoxaemia; part of a sleep disorder such as COPD and obstructive sleep apnoea (OSA); or it may be sleeping disturbance as part of a chronic disease and mood disorders.
As part of improving the symptoms for any chronic disease, assessing what might happen at night in sleep can improve feelings of wellbeing and can improve disease outcomes. Assessing sleep in respiratory disease is more than just OSA, there can be many causes.
During sleep several changes take place that can alter respiratory function. Ventilatory drive reduces in sleep, more so in REM sleep compared with non-REM sleep.
Anything that further impacts on ventilation can make things worse. This includes upper and lower respiratory muscle function, which can also be impacted by an increased load (obesity).
The fluid shifts occurring normally when changing from upright to supine also impact on the upper airway size. This can be more so in co-morbid heart failure, which can also contribute to pulmonary congestion and reduced lung compliance.
Changes in airway function and size during sleep as well as changes in ambient air, such as temperature, may contribute to sleep disturbance, for example when asthma is not optimally controlled.
This can mean that anything that impairs breathing – airway narrowing (COPD), lung stiffness (ILD), chest wall compliance (obesity) – can make breathing worse, reducing oxygen and raising carbon dioxide.
Co-morbidities and side effects
As with any chronic disease, sleep can be impacted by poor mood, anxiety and depression. As with other chronic diseases, there are common co-morbidities with chronic respiratory disease.
Concerns regarding the impact of the disease on family, risks of exacerbations and illness, and hospitalisation are major contributors to poorer mood and impaired quality of life, especially in COPD.
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The life shortening which results from lung disease such as ILD and COPD are also significant factors in poorer mental health.
Treatment side effects can negatively impact sleep. Corticosteroid therapy either as short-term high dose or long-term can negatively impact mood and is associated with insomnia.
Long-term steroid therapy leading to osteoporosis and fracture can impact sleep due to pain.
Nocturnal oxygen therapy can lead to nasal symptoms with dryness and epistaxis, as well as discomfort form the delivery system – usually nasal cannula. PAP therapy, if used thoughtfully and with good patient education, is often beneficial but can impact sleep quality if not properly set up.
Sleep assessment
Assessing sleep in patients with chronic respiratory disease initially can be done on history – how do they sleep, what issues do they have with sleep.
Disease specific questionnaires have sleep related questions, for example the COPD Assessment Test (CAT) and the Asthma Control Questionnaire (ACQ).
Sleep quality questionnaires, such as Epworth Sleepiness Score and Pittsburgh Sleep Quality Index, are more sleep specific and the DAS (Depression and Anxiety Scale) can be helpful in identifying mood changes in patients.
A sleep study may be beneficial, particularly if there is a consideration of OSA, hypoxaemia or hypoventilation in sleep. Whether a home or a lab sleep study is better may depend on the specific question, but the assessment of the study in the context of the patient is imperative, as is the discussion and supervision of any therapy.
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Management of the other causes of poor sleep in this patient group, however, can be more challenging. Pharmacological management of insomnia is ideally only short term.
Psychological and behavioural strategies are better long-term options, but access to therapies like CBT-I can be difficult and cost can be a deterrent.
Medication to improve anxiety, help with sleep and manage pain can all have the potential issues of respiratory depression. Generally, careful supervision and starting with low doses is safe.
Informing the patient and family of what to look out for can avoid significant respiratory depression. Balancing the positive with the negative effects may bring about an acceptable positive response with tolerable side effects.
Author competing interests – nil
Key messages
- Sleep is important for wellbeing both physical and mental. Poor sleep can have a substantial negative impact on patients with chronic lung disease
- In these patients, the impact on sleep may be part of the disease, be related to the treatments or be part of the psychological impact of poor health
- Assessment is important and although management may be challenging, it may provide some positive benefits for patients.
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